1. Technical Field
The present invention relates to quality control in, and technology for facilitating support of; analyzers.
2. Description of Related Art
Blood tests and other forms of clinical examination require that samples such as blood and urine be analyzed for a variety of test items. Analyzers that employ assaying methods suited to the characteristics of the analysis items perform sample assays. Analyzers have sophisticated mechanisms that allow them to assay, with a high degree of sensitivity, extremely low concentrations of a substance, and to assay trace amounts of sample for ten or more items. To maintain the accuracy of the test results, operations in each of the mechanisms are monitored.
When problems arise in operation of the mechanisms, the analyzer issues a warning to that effect, alerting the user to the problem in the analyzer. In such cases, a user will deal with the problem by following the operating manual or, for example, by calling a support center, explaining the circumstances, and following the instructions of the technician. When the user cannot take care of it single-handedly, the support center dispatches a technician to do so.
Nevertheless, in clinical testing, merely monitoring the analyzer mechanisms is insufficient for governing test results on vital components with satisfactory accuracy. Quality control is therefore performed. Samples identical with the vital components, or samples that are their analogues, are assayed as quality control substances, and the assay results are monitored.
Both internal and external methods are utilized for quality control. Internal quality control is a method of assaying identical quality control substances daily with the same analyzer, and monitoring whether stable assay results are being obtained. External quality control is a method of monitoring whether assay results that are being obtained are the same as results assayed by an identical analyzer employed outside those facilities.
In order to carry out external quality control, however, the same quality control substance has to be sent from a statistical tallying center to each facility; the quality control substance has to be assayed at each facility; those assay results (“sample data” hereinafter) have to be sent from each facility to the statistics center; and the sample data has to be tallied by the statistics center. This means that the facilities first learn of the external quality control results when the tally is sent back from the statistics center. From the time the quality control substance is sent out until the time the tally is returned routinely takes one to two months. Sometimes it is necessary to wait until the statistics center accumulates a set number of sample data returns.
A first issue the invention addresses relates to measures taken when trouble has arisen. Because today's analyzers are operated under the control of sophisticated programs, instances in which a user is unable to cope with the problem single-handedly are increasing. When such is the case, the user has to wait until a technician visits to deal with the problem.
The only option is to wait for the technician's visit if a systematic problem can only be resolved by changing out or adjusting an analyzer component. Nevertheless, these are not the only reasons users cannot cope with breakdowns single-handedly. There appear to be many cases in which users ought to be able to resolve the trouble on their own. In some instances, the trouble in the analyzer is not resolved because the user cannot adequately explain the status of the problem; in others, the user cannot properly carry out the analyzer operations necessary to resolve the trouble.
Because assay is not possible while an analyzer is down, patient test results in clinical examination cannot be reported to the diagnosing physician. For samples like blood which has low preservation stability, delaying the assay by one day would mean lower accuracy in the test results, and therefore blood has to be drawn from the patient again.
A second issue the invention addresses is that, with external quality control, as described above, confirmation can be obtained is only by waiting for the tally from the statistics center. This normally is done once a year, and at most on the order of only three or four times a year.
To raise the reliability of assay data per se, quality control by definition should be carried out and the results checked before each day's sample assays. In other words, if the quality control sample data falls outside a predetermined range, this can mean that something has gone wrong and that the analyzer is not in sufficient working order. Sample assay should be carried out following adjustment of the analyzer to bring the data within the predetermined range. With current external quality control, however, the tally results come back one or two months after assay, and are used for no more than confirming after-the-fact the status of the device at the time assay was made.
Wherein a substance such as blood that is liable to transform (denature) over time is the assay subject, the freshness of the quality control substance employed in the sample data assay must be at the same level among each of the facilities taking part in external quality control. When quality control substances are sent out to facilities to collect sample data, inevitably the assaying tends to be performed on different days at different facilities Accordingly, because the freshness of the quality control substances that are the basis for the sample data collected tends to vary, the reliability of the tally results is diminished.